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Brachycephaly (BR-BMP3)

Brachycephaly (BR-BMP3)

Flat face, shortened snout

Brachycephaly is a skull shape trait seen in a number of breeds and is characterized by a shortened head, pushed-in face, and typically an underbite with widely spaced shallow orbits. Breeds known to exhibit this trait include Pugs, Boxers, Bulldogs, and Boston Terriers. The overall shape and size of a dog’s skull are likely the result of multiple genetic factors with a mutation in the BMP3 gene being one factor contributing to a short muzzle. BMP3 is also suspected to be essential for normal craniofacial development with mutations in this gene likely leading to abnormal craniofacial development. This mutation is typically fixed or carried in two copies in breeds such as Pug, Pekingese, French Bulldog, Brussels Griffon, and Boston Terriers. Additional mutations such as SMOC2 are currently being studied to determine their effect on skull development and brachycephaly.

Reading Your Results


These dogs have two copies of the normal gene and will likely not have a short muzzle length nor pass this mutation to their offspring.


These dogs have one copy of the normal gene and one copy of the mutation associated with this trait. They will likely not have a short muzzle length but will, if bred, pass the mutation to 50% of its offspring, on average.


These dogs have two copies of the mutation associated with short muzzle length in some breeds.

Additional Details



Affected gene



Ch. 32




Schoenebeck JJ, Hutchinson SA, Byers A, Beale HC, Carrington B, Faden DL, Rimbault M, Decker B, Kidd JM, Sood R, Boyko AR, Fondon JW 3rd, Wayne RK, Bustamante CD, Ciruna B, Ostrander EA. Variation of BMP3 contributes to dog breed skull diversity. PLoS Genet. 2012;8(8):e1002849. [PubMed: 22876193]